000
AXPZ20 KNHC 090350
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN JAN 09 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 7N81W
TO 5N92W TO A 1008 MB LOW NEAR 8N108W TO 6N121W TO 5N130W TO 
4N140W. NO SIGNIFICANT CONVECTION IS NOTED.

...DISCUSSION...

A SURFACE RIDGE EXTENDS SE INTO THE AREA THROUGH 32N127W TO
23N120W TO 20N113W. WELL TO THE NW OF THE AREA A 1000 MB GALE 
CENTER IS NEAR 31N155W. AHEAD OF IT...A STATIONARY FRONT LIES 
ABOUT 240-300- NM W OF THE AREA. THE PRES GRADIENT BETWEEN THIS 
SYSTEM AND THE RIDGE IS AFFECTING THE AREA N OF 23N W OF 135W 
WITH SE-S WINDS OF 20-25 KT. THESE WINDS ARE EXPECTED TO 
CONTINUE THROUGH THE NEXT 24 HOURS...THEN DIMINISH SOME BY 48 
HOURS WITH SEAS OF 8 TO 12 FT IN LARGE NW SWELLS...SUBSIDING TO 
10 FT BY 48 HOURS.

ELSEWHERE A RELATIVELY PRES GRADIENT EXISTS THROUGHOUT...WITH 
THE EXCEPTION OF THE SOUTHERN PERIPHERY OF THE RIDGE FROM 
7N TO 20N BETWEEN 110W AND 130W WHERE THE GRADIENT SUPPORTS NE TO
E WINDS OF 20 KT WITH SEAS OF 8 TO 10 FT IN NW SWELL. AN ASCAT 
PASS FROM YESTERDAY AFTERNOON SHOWED THESE WINDS. ELSEWHERE FROM 
6N TO 20N W OF 110W AND S OF 6N W OF 129W WINDS ARE LESS THAN 20 
KT WITH SEAS 8 TO 10 FT IN LARGE NW LONG PERIOD SWELLS.

SATELLITE WATER VAPOR IS SHOWING A HIGHLY AMPLIFIED MID/UPPER 
LEVEL RIDGE EXTENDING FROM 32N136W SE TO 20N128W TO NEAR 
13N121W. TO ITS W...A VERY PRONOUNCED LARGE DEEP LAYER TROUGH IS 
JUST W OF THE REGION WITH SEVERAL SHORTWAVES ROTATING THROUGH 
IT. THIS ENTIRE SYSTEM IS SUPPORTING THE ABOVE MENTIONED GALE 
CENTER AND FRONTAL SYSTEM. EXTENSIVE MOISTURE IS BEING CHANNELED 
FROM THE CENTRAL PACIFIC AHEAD OF THE TROUGH INTO THE FAR 
WESTERN SECTION OF THE AREA. SCATTERED SHOWERS AND TSTMS WITH 
POSSIBLE STRONG GUSTY WINDS ARE JUST CROSSING 140W N OF 17N AS
THEY PRESS EASTWARD. THE UPPER LEVEL MOISTURE FIELD SPREADS 
EASTWARD UP AND OVER THE MID/UPPER LEVEL RIDGE WITH A TRAJECTORY 
EASTWARD TOWARDS FAR SOUTHERN BAJA CALIFORNIA AND NW MEXICO.

A SHORTWAVE TROUGH IS NOTED OVER THE FAR NE PORTION OF THE AREA
SWINGING EASTWARD AS IT STRETCHES FROM THE SW U.S. SW TO OVER
CENTRAL BAJA CALIFORNIA AND TO 18N114W. MODERATE SUBSIDENCE AND 
ASSOCIATED DRY AIR DUE TO THE SUBSIDENCE AREA IS QUICKLY BEING
REPLACED BY THE UPPER LEVEL MOISTURE TO ITS W.
 
SATELLITE IMAGERY IS ALSO SHOWING SCATTERED MODERATE CONVECTION
WITHIN 120 NM OF THE LOW NEAR 8N108W IN THE NE AND E QUADRANTS.
AN ASCAT PASS FROM YESTERDAY REVEALED SE TO S 20 TO 25 KT WINDS 
WITHIN 90 NM OF THE LOW IN THE SE QUADRANT. THE PASS ALSO SHOWED 
SLY 20 KT WINDS FEEDING INTO THE CIRCULATION ELSEWHERE S OF THE 
LOW BETWEEN 105W AND 109W. THE GLOBAL MODELS CONTINUE TO 
FORECAST THE LOW TO TRACK IN A GENERAL WNW DIRECTION OVER THE 
NEXT 48 HOURS WHILE REMAINING RATHER. SATELLITE DERIVED WINDS
AND ANALYSIS FROM CIMSS ALONG WITH THE LATEST WATER VAPOR IMAGERY
INDICATE THAT THE UPPER LEVEL ENVIRONMENT OVER THIS LOW HAS
BECOME RATHER HOSTILE AS UPPER LEVEL WLY WINDS CONTINUE TO 
INCREASE IN SPEEDS. THIS WILL IMPINGE ON THE CURRENT CONVECTION
BEING OBSERVED BY WEAKENING IT UNDER RESULTANT SHEAR THROUGH
THE NEXT 12-24 HOURS.

$$
AGUIRRE